4DATLANTIC Dust-Ocean Modelling & Observing Study (DOMOS)

The Dust-Ocean Modelling & Observing Study (DOMOS) will advance the understanding of dust and ocean interactions in a changing climate through an innovative use of model and observations. The project will develop a new retrieval of dust deposition from satellite lidar data (CALIPSO and Aeolus), will validate the dust deposition field from the CAMS reanalysis and will also provide assimilation tests of IASI and Aeolus aerosol products with the goal of providing a better description of the dust aerosols, for applications in aerosol radiative impacts and ocean biogeochemistry. An improved representation of the physical and chemical characteristics of dust deposition over the ocean is crucial to interpret the observed climatic change responses and to better describe the future ones. This includes a better understanding and quantification of the deposition of soluble iron from natural and anthropogenic dust and of its contribution relative to biomass burning and anthropogenic aerosols which will be one of the main deliverables of the project. A scientific roadmap to highlight the findings of the project and identify possible gaps in the modelling and the observing approaches will also be provided.

DOMOS aims to answer the following questions.

1. To what extent dust deposition over the Atlantic has changed over the last 20 years? Can we identify robust trends in the reanalysis and model datasets and if yes, how can we verify them? Although estimates have been attempted before, there is the need to look at longer time-series such as those provided by atmospheric composition reanalysis and climate models and develop tailor-made satellite retrievals from multiple sensors and platforms, aimed at quantifying dust deposition. This is a challenge as dust deposition is not directly observable from satellite. Observations must be complemented with model-based information. Also, independent observations of dust deposition are needed to quantify the quality of the model-based and reanalysis-based reconstructions as well as to evaluate the performance of the bespoken satellite retrievals.
2. What is the contribution of anthropogenic and natural sources of dust compared to biomass burning and anthropogenic aerosols to soluble iron deposition over the Atlantic? While dust is the largest contributor to total iron deposition by far, it is unclear what its contribution to soluble iron deposition is.
3. What are the impacts of changes in dust deposition on marine biogeochemistry and their potential effects on ecosystems? The connection between changes in dust deposition and the nutrients available for marine ecosystems needs further investigation with a concerted synergy of modelling and observations.